Let's talk about what you need to spend on a good mountain bike. Bikes can run anywhere from a couple of hundred bucks into the high thousands. Why? The components.

Bikes are in many ways like stereo systems. If you've ever gone into a high-end stereo shop, you may have noticed that the best, highest priced systems have what are called "separates:" separate amp, tuner, pre-amp, equalizer, CD player, etc. As you come down in price, you also go up in convenience: More of these functions are combined into one chassis, all the way down to the ultimate convenience machine, the boom box. Same with bikes.

The bike you drive actually consists of a frame, a chain, rear and front deraileurs (the device that moves the chain from the big rings to the small rings when you shift gears), the shifters and the wheels. You can buy each of these separately and spend a fortune, or you can get a basic model in which everything is already put together.

According to top cycling coach and personal trainer Terry Kerrigan of the Equinox Fitness Clubs in New York, beginners spend far too much on basic equipment. "Great bikers have won races with basic stuff," says Terry. "Aerodynamics win races; aerodynamics plus the motor, which is you." Terry's advice: Get the best frame you can, and the most basic components. You can upgrade the components as your interest and skill level improve, but you may even find that the basics serve you just fine.